當前位置：首頁 > 运维知识 > 数据库 >内容正文

数据库

MySQL子查询操作实例详解

發布時間：2024/4/18 数据库 23 豆豆

生活随笔收集整理的這篇文章主要介紹了 MySQL子查询操作实例详解小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

本文實例總結了MySQL子查詢操作。分享給大家供大家參考，具體如下：

定義兩個表tb1和tb2

1 2	CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL);

向兩個表中插入數據：

1 2	INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20);

any some關鍵字的子查詢

SELECT num1

FROM tbl1

WHERE num1 > ANY (SELECT num2 FROM tbl2);

all關鍵字的子查詢

SELECT num1

FROM tbl1

WHERE num1 > ALL (SELECT num2 FROM tbl2);

exists關鍵字的子查詢

SELECT * from fruits

WHERE EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

SELECT * from fruits

WHERE f_price>10.20 AND EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

SELECT * from fruits

WHERE NOT EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

帶in關鍵字的子查詢

SELECT c_id

FROM orders

WHERE o_num IN (SELECT o_num FROM orderitems WHERE f_id = 'c0');

SELECT c_id

FROM orders

WHERE o_num NOT IN (SELECT o_num FROM orderitems WHERE f_id = 'c0');

帶比較運算符的子查詢

SELECT s_id, f_name FROM fruits

WHERE s_id =

(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

<>所有非

SELECT s_id, f_name FROM fruits

WHERE s_id <>

(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

定義兩個表tb1和tb2

1 2	CREATE table tbl1 ( num1 INT NOT NULL); CREATE table tbl2 ( num2 INT NOT NULL);

向兩個表中插入數據

1 2	INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20);

【例.53】返回tbl2表的所有 num2 列，然后將 tbl1 中的 num1 的值與之進行比較，只要大于 num2的任何值為符合查詢條件的結果

SELECT num1

FROM tbl1

WHERE num1 > ANY (SELECT num2 FROM tbl2);

【例.54】返回tbl1表的中比tbl2表num2 列所有值都大的值

SELECT num1

FROM tbl1

WHERE num1 > ALL (SELECT num2 FROM tbl2);

【例.55】查詢表suppliers表中是否存在s_id=107的供應商，如果存在則查詢fruits表中的記錄

SELECT * from fruits

WHERE EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

【例.56】查詢表suppliers表中是否存在s_id=107的供應商，如果存在則查詢fruits表中的f_price大于10.20的記錄

SELECT * from fruits

WHERE f_price>10.20 AND EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

【例.57】查詢表suppliers表中是否存在s_id=107的供應商，如果不存在則查詢fruits表中的記錄

SELECT * from fruits

WHERE NOT EXISTS

(SELECT s_name FROM suppliers WHERE s_id = 107);

【例.58】在orderitems表中查詢訂購f_id為c0的訂單號，并根據訂單號查詢具有訂單號的客戶c_id

1 2	SELECT c_id FROM orders WHERE o_num IN (SELECT o_num FROM orderitems WHERE f_id = 'c0');

【例.59】與前一個例子語句類似，但是在SELECT語句中使用NOT IN操作符

1 2	SELECT c_id FROM orders WHERE o_num NOT IN (SELECT o_num FROM orderitems WHERE f_id = 'c0');

【例.60】在suppliers表中查詢s_city等于Tianjin的供應商s_id，然后在fruits表中查詢所有該供應商提供的水果的種類

SELECT s_id, f_name FROM fruits

WHERE s_id =

(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

【例.61】在suppliers表中查詢s_city等于Tianjin的供應商s_id，然后在fruits表中查詢所有非該供應商提供的水果的種類，SQL語句如下：

SELECT s_id, f_name FROM fruits

WHERE s_id <>

(SELECT s1.s_id from suppliers AS s1 WHERE s1.s_city = 'Tianjin');

更多關于MySQL相關內容感興趣的讀者可查看本站專題：《MySQL常用函數大匯總》、《MySQL日志操作技巧大全》、《MySQL事務操作技巧匯總》、《MySQL存儲過程技巧大全》及《MySQL數據庫鎖相關技巧匯總》

總結

以上是生活随笔為你收集整理的MySQL子查询操作实例详解的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。